I think the reason why my E288CC works so well in the CSP2+ is because they are 2x the gain spec of a normal ECC88/6922 with current demands accordingly higher than normal. It is akin to a only slightly weaker version of the 6N1P.

But the silver lining is that you just need 1 super good tube in the frontal position to enjoy the sonic benefits. The Telefunken E88CC sounds superb too with a wonderful midrange.

Lon here is already having a blast with the Russian 6N1P-EV tubes and he has 3 CSPs now!!!Steve also voiced the amp with the Russian tubes so anything else has to be treated as a gamble.

I will report back over here eventually on whether my existing tube complement can work equally well on the CSP3.

Lord Soth:Lon here is already having a blast with the Russian 6N1P-EV tubes and he has 3 CSPs now!!!Steve also voiced the amp with the Russian tubes so anything else has to be treated as a gamble.

Lord Soth,

I have to agree with Lon that the 6N1P-EV, in my case, cryo'd 6N1P-EVs, provide excellent results with the CSP3. I do believe that my super duper Telefunkens overall did sound better (after the turn-on thumping noise died down) but, I wasn't willing to risk damage to the tubes, speakers or equipment, so I removed them from the driver positions in the CSP3, and put one each into the input position of the CSP3 and the Taboo III. I still get most of the Tele's sonic benefits this way. At present, the sound of the CSP3/Taboo III via my Omega 3Es is so good that further tube rolling, for me, is unnecessary. When Steve's new Silver ICs arrive, I probably will be done fiddling (or so I hope). I'll just sit back and enjoy the music....that is, until Steve drags me back in with a new toy.

Rizlaw, I look forward to your thoughts on the Decware interconnects. And thanks for your input from your research and listening to the CSP2+ and CSP3.

Lord Soth, that is interesting about the E288CC. I had not considered this tube and am glad to be introduced to it.

The 6922 type in the CSP3 output postion is mysterious to me. It sounds like from Rizlaws reading that the CSP2+ and CSP3 are basically the same circuit, so one would certainly think your current tubes would work LS.

On the other hand, apparently the 6922 types are not a real option in my CSP3. I have not tried them all, but have tried 10 pair that seemed promising with high scores and that seem truly NOS. None of my 6922, 6DJ8, 623NP or 7DJ8s work, including some hardly used National 7DJ8s premium matched from Upscale...perhaps close, but apparently not like Rizlaw's.

On the other hand, the four pair I have of 6N1P all work fine.

Steve and I touched briefly on this the other day, but my attention took us elsewhere before I fully understood it. If I got it right???? it does seem that the way the circuit uses two triodes (I think in series) to create the SRPP power output is where the rub is. It would be interesting to get the skinny from Steve what the tube requirements are in this case....what defines strong. I just get so jazzed talking with him about audio and Decware gear, I lost that track and moved to new territory.

Personally, the 6N1P has not been a fav, but it does seem integral to the tangible beauty the CSP3 brings to the table! And there is a lot that can be done with the input and rectifier. So I look forward to more breakin and exploration with this beautiful music tool.

I am using some new old stock GE 6BQ7A tubes in my CSP2+. They were from bulk, marked Tektronics for use in their scopes. I bought a set of 10. Unfortunately, one of them was a dud when I first tested them. Another one after using it for a while started making a fuzzy noise. The other 8 I have work fine. They don't hiss, crack or spit in that SRPP circuit like some other tube types did. The 6N1P is very rugged and every one I've tried will withstand the SRPP circuit. Since the 6BQ7 is electrically nearly identical ti the 6N1P it will withstand the rigors of the circuit.

I've tried 6BQ7 tubes when you pointed out to me that they are electrically very similar to 6N1P. However. . . I didn't prefer them to 6N1P in either the CSP2, CSP2+ or Torii. I stick with the supercryo'd 6N1P, the tubes that sound most "real" to me when listening to the recordings I made of bands I was in in the 'eighties.

Thanks for the tip Rivieraranch, and for your thoughts on the 6BQ7A Lon. Unlike the E288CC, these are so cheap I just ordered a couple pair to check out for fun. I am actually really enjoying a 6N1P a bunch for the first time, so this may be unnecessary, but couldn't help it. I found some uncryo'd black plate 6N1P with a 17 in the diamond, and with a Sylvania 7308 in front and a 50's GE (RCA) 5U4G-ST (one with the lighter duty black plates in the T part where they go over the support rods) I have a truly great sound happening. Feels like this is in part the CSP3 breaking in more too... but it is good!

Thanks for the reminder Lon. I tried my RCA and Hytron 5Y3GTs and found them a bit flat...but this was by comparison, and the RCA 5U4G, Valvo 274B and Chatham 5R4WGY are all quite dynamic and open seeming, which could be tricking me, their being more exciting as I burn the thing in. After I get it burned in, I may not prefer the bolder sound.

Based on your experience, I will definitely explore the 5Y3s when things are settled in. They do have a sweet warmth and texture that I love.

Glad to see you seem to have the problem in hand and are now enjoying 6N1Ps. You're right, the Russian NOS 6N1P-EVs are significantly cheaper than the NOS 6DJ8 family of tubes; built to last a long time, and sonically not that far behind the best European and American NOS tubes.

I was doing a little more searching on the SRPP circuit and found these two sites which may or may not be of interest regarding the circuit:

ConclusionWhich circuit would I build? The latter, as it would provide the cleanest output, which would outweigh the need for extra parts in my judgment. (I would actually use a 6H30 instead of a 6SN7 and a 6N1P instead of the 6SL7.)

The ECC88, or its American equivalent, the 6DJ8, are the best sounding tubes in current production for utilization in a SRPP stage. The E88CC and 6922 also sound good and are known for a long life span under professional operating conditions. The 6922, produced for the American military, is exceptionally good, and its Russian counterpart also delivers excellent results. Other than a slightly higher heater current, the PCC88 is identical. Its high slope (12 mA/V) results in a low-impedance output, while the signal to noise ratio ,equivalent of 300 ohms, results in quiet operation, but its high amplification also amplifies noise.

It seems like the tubes you previously tried should have worked, too. I may have to try a 5Y3GT just to see if I agree with Lon. I do agree with you about the 274B sound.Enjoy the CSP3.

The 5Y3GT rectifier by either RCA or Tung Sol is superb in the CSP2+.The CSP was built based on the 5Y3 rectifier so as long as one replaces the stock Sovtek or Chinese rectifier with an Amercan one, it should put a big smile on your face.

It only costs US$20-25 for a NOS / NIB.

Whether you prefer one over the other is a matter of personal preference.

If I were stuck on a deserted island, I could happily live with just the Russian 6N1P-EVs and a NOS Tung Sol 5Y3GT in my CSP2+.

Rizlaw. I don't get those articles...I must be getting denser. I would have to do some translating of terms to begin to get it, not being electronically savvy, but I am convinced from tube play to just hang with the 6N1P for now, and this is good. I would guess that the tube type in an SRPP circuit would likely determine different resistor and cap value latitudes though...

Anyway, I have been playing with tubes still and am currently staying with the GE/RCA 5U4G-ST, the black plate 6N1Ps, and now an ERR (Mullard) 6DJ8 in front. For me, just now, the 5Y3GTs are still a little too flat in dynamics, weight and power.

With the tubes I have in though, I love the dynamics, detail and textures within the lovely and musical cloak of warmth and body. What a pleasure this CSP3 is. I would never have guessed it would be this enjoyable. The way it solidifies the bass and weight on my somewhat errant Torii MkIII bass area is just beautiful. It does its magic everywhere actually! What a tool!

Cool will, glad you are digging the preamp. As soon as I got a ZStage and put it into my Dad's system a bit ago I thought to myself "This is a neat component, but it's not a CSP2 or CSP2+, I bet will would really like one of those." And now you have one.

Over time I've learned that adjusting the gain can really be a great tool to fine tune the system; I find that the lowest gain I can use that allows me the max volume for the component with the weakest output really gets things balanced for me.

Thanks for the gain tip Lon. I found your initial adjustment parameters very helpful. And you were right. Will really does like this thing!

It is interesting. Aside from adding another tube and the even order harmonics this provides, I find the Zstage with the Jupiter caps to be very transparent in the true sense of the word. It just does what it does beautifully without imparting color other than that of the tube you use, and weight and body from the gain riding. It is really good at providing whatever qualities the tube you use has. An excellent tool for tuning an amp with another very well implemented tube, and for tuning individual recordings with the riding.

I would not exactly call the CSP3 transparent, but I totally love what it does. And what it does, it does with such finesse that it has all the hallmarks of transparency....all the detail is there within its lovely warm (but not dark) signature, the bass is deep and solid, the mids and highs are musical, sweet and clear, and the punch and dynamics are pretty much any way you want. But transparent???? It feels that way, but I can't quite say that. But then I think - who cares! This thing is just a really good musical tool.